<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>hello</title>
    <script type="text/javascript" src="vue.js"></script>
</head>
<body>
        <div id="app">
            {{name}}
        </div>
        <script>
           /*  var dom = document.getElementById('app');
            dom.innerHTML = 'hello ,welcome'

            setTimeout(function(){
                dom.innerHTML = 'hello, index'
            },2000) */
            var app =  new Vue({
                el:'#app',
                data:{
                    name:'hello ,vue'
                }
            });
            
            setTimeout(function(){

                app.$data.name = 'buy ,vue'
            },2000)
        </script>
</body>
</html>